The present invention relates to an airbag for protecting the head of a vehicle occupant, and more particularly, to a head protection airbag which is constructed so as to be deployed along a side door pillar and the like upon a side impact or a roll-over of a vehicle. Also, the present invention relates to a head protection airbag device having the head protection airbag.
As is generally known in the art, an airbag for protecting the head of a vehicle occupant is installed adjacent to a corner of a vehicle interior where a roof panel and a side panel are joined to each other, and is constructed so as to be deployed along a side door window and the like when gas is introduced therein from an inflator through a gas inlet.
International Publication No. WO 97/06987 (hereby incorporated by reference herein in its entirety) discloses a side airbag which is deployed on the side of a vehicle occupant. In the side airbag, a longitudinal intermediate portion of a bag is constricted by a seam which extends in a transverse direction (a lengthwise direction of a vehicle body: this also applies to the following description), so that the bag is divided into an upper portion and a lower portion. A panel is positioned along a portion of the airbag which faces the vehicle occupant. The upper and lower portions of the panel are respectively connected to the upper and lower portions of the bag. When the bag is inflated, the panel is tightly stretched. Then, as the shoulder of the occupant comes into contact with the bag, the panel pulls the upper portion of the bag downward. As such, the upper portion of the bag is pulled toward the vehicle occupant to protect the head of the vehicle occupant.
Japanese Unexamined Patent Application Publication No. 2003-72500 discloses an airbag for protecting the head of a vehicle occupant (hereby incorporated by reference herein in its entirety). In this type of airbag, supporting fabric is positioned on the sides of a bag which faces both a vehicle occupant and a vehicle body. The upper and lower edges of the supporting fabric are coupled to the upper and lower edges of the bag.
In the case where the airbag disclosed in International Publication No. WO 97/06987, which has the panel positioned so as to face the vehicle occupant, is employed as a head protection airbag, when the head of the vehicle occupant comes into contact with the panel, since the lower portion of the bag is also pulled toward the vehicle occupant, a tensile force is not sufficiently generated in the panel, and therefore, the panel cannot properly protect the head.
In the case of the head protection airbag disclosed in Japanese Unexamined Patent Application Publication No. 2003-72500, the supporting fabric contributes to the protection of the occupant's head. However, in order to ensure that the airbag or the supporting fabric immediately catches the head of the vehicle occupant, the thickness of a connection member of the airbag needs to be increased, which consequently increases the size of the airbag. As a result, it is necessary to employ an inflator having a large capacity.
Accordingly, it is an object of the present invention to provide a head protection airbag which eliminates the need to employ an inflator having a large capacity and which is capable of immediately protecting the head of a vehicle occupant, thereby sufficiently absorbing a shock applied to the head of the vehicle occupant, and a head protection airbag device having the head protection airbag.